The Book of Faith (Kitab Al-Iman)
Muslim :: Book 1 : Hadith 54
It is narrated on the authority of 'Abbas b. 'Abdul-Muttalib that he heard the Messenger of Allah saying: He relished the flavor of faith (Iman) who became the book of faith pleased with Allah as Lord, with al-Islam as the code of life and with Muhammad as the Messenger (of Allah).